Let $R (a, b, c)$ and $S(d, e, f)$ be two relations in which $d$ is the foreign key of $S$ that refers to the primary key of $R$. Consider the following four operations $R$ and $S$
Insert into $R$
Insert into $S$
Delete from $R$
Delete from $S$
Which of the following can cause violation of the referential integrity constraint above?
Both I and IV
Both II and III
All of these
None of these
Insert into R cannot cause any violation.
Insert into S can cause violation if any value is inserted into d of S, which value is not in a of R.
Delete from S would cause no violation.
Delete from R would cause violation if it any tuple is deleted,and as a result a value in a gets deleted which is refereed to by d in S.
When will be the final official key...